EXPIRED PS CHOCLATE

I BOUGHT A PS BAR AT PARK CENTRAL PEP JOHANNESBURG, WHEN I ATE IT IT TASTED STALE BUT I DIDNT NOTICE. I HAD A RUNNING TUMMY AND I DIDN'T FINISH THE CHOCOLATE, SO NOW IM AT WORK AND TRYING TO FINISH THE CHOCOLATE AND I NOTICE ITS EXPIRED ON 07-04-16. THE CHOCOLATE WAS BOUGHT ON 09-04-16 AND THE EXPIRY DATE IS 07-04-16, THIS MEANS THE STOCK IS NOT CHECKED AND I WAS HOPING THAT THE STAFF SHOULD CHECK THE EXPIRY DATES ON SUCH PRODUCTS, IS IT SAFE THEN TO BUY A CHOCOLATE AT PEP???